Trim tabs are used to improve the glide angle of watercraft, which by changes in the direction of flow shift the corresponding uplift zones in order to facilitate more favorable weight distribution and or to start the vehicle gliding faster, as described in U.S. Pat. No. 3,628,487 or U.S. 2004/0014376 A1.
Recently other systems have also been marketed, such as submersible flow interceptors, described in Patent TW499382B or also U.S. Pat. No. 6,006,689.